Fix the order of configuration calls

Since _SetDrbdHelper calls methods on self.cfg, it's necessary to update
the configuration before it is called.
Signed-off-by: Petr Pudlak <pudlak@google.com>
Reviewed-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Hrvoje Ribicic <riba@google.com>

lib/cmdlib/cluster.py

@@ -1500,8 +1500,8 @@ class LUClusterSetParams(LogicalUnit):
 
     self.cluster = self.cfg.GetClusterInfo()
     self._SetFileStorageDir(feedback_fn)
-    self._SetDrbdHelper(feedback_fn)
     self.cfg.Update(self.cluster, feedback_fn)
+    self._SetDrbdHelper(feedback_fn)
 
     # re-read the fresh configuration again
     self.cluster = self.cfg.GetClusterInfo()